On small lakes in the evenings (lake Alice is a favorite) I use a floating Rapala with one split shot about 2 feet in front of the plug. This is just enough weight to keep the plug lip digging into the water so the plug will dive a little. I've had good luck with Rainbow, Perch, Fire tiger, and a bright neon yellow Rapala, the smaller the better.

I would also recommend removing the front set of hooks on the plug, since it is one less thing to get tangled in the net or your hide when you've got a whopper flailing around in the boat.

When trolling, zig-zag or "S" turn, this changes the action, speed, and depth of the lure often enticing a strike. GOOD Luck.